In recent years, the use of solar energy has become increasingly important as an alternate source of energy. Such a system is useful in an area having plentiful sunlight but little conventional energy resources. However, a photovoltaic array having a useful capacity is relatively expensive, and it is therefore important that it be operated at maximum efficiency conditions.
Numerous systems have been proposed and utilized for extracting the maximum power available from an array under varying conditions. As is well known, the available power varies with changes in the solar radiation level and the ambient temperature, and such systems include a power matcher for operating the system at peak power conditions. Prior art power matchers include the use of a temperature compensated reference voltage, the use of a pilot or reference photovoltaic cell, and means for measuring the power over a range of power outputs and then adjusting the system to the peak power point.
These foregoing prior art systems have the disadvantage that they only approximate the peak power point, or that their response time is too slow to make them usable in all types of power systems.
It is a general object of the present invention to provide an improved power matching system that is operable under various conditions, accommodates various arrangements of photovoltaic cells, and responds rapidly to changes in operating conditions.